Floating support for well tubings



March 26, 1957 T. A. CREIGHTON 2,786,532

FLoATING SUPPORT lFOR WELL TUBINGs T 6 u 55 f; :9. 3.

1N VEN TOR. f2 .7l/@Ms CQE/GHTOM 11 `the tubing. upper end, so that' it is not adversely affected by temper- 2,786,532 Patented Mar. 26,1957

FLOATING SUPPORT FOR WELL TUBNGS Thomas A. Creighton, Long Beach, Calif., assigner, by direct and mesne assignments, of one-half to Vera Neva Creighton and one-half to Ethel Claire Creighton Application May 17, 1949, Serial No. 93,707 13 Claims. (Cl. 166-73) This invention relates to oil wells; more particularly it relates to apparatus for supporting the well casing at the mouth of a well bore.

In an oil well, the well bore is commonly lined with a string of pipe or casing supported at its upper end as by being secured to a casing head or the like at the surface, and extending downwardly to a point above. the oil strata, where, prior to the completion of the well, it is cemented to the earth formation to seal oli the water sands thereabove. The casing is appropriately tensioned when so installed, by the aid of the casing head, but thereafter conditions may arise, such for example as `temperature changes, or relative movement of the earth formation which Cause undesirable -and dangerous variations in the tension. Thus, the tension may be increased suciently to cause the casing to break loose at either or both of its ends, or to part at an intermediate point, or the tension may be reduced to such an extent fas to cause buckling and collapse of thefcasing.

It is accordingly an object of this invention toprovide apparatus for maintaining a casing string or the like under suitable tension throughout a predetermined range of variations in the operating conditions thereof.

It is another object of.. this invention to provide apparatus by the aid Vof whichthe tension in a casing is 4readily adaptablefor use with diiferent sizes of casing.

Producing oil wells usually includes a tubing string extending downwardly within the casing to the productive zone', the il flowing upwardly throughthe tubing in r'esponsey to gas pressure yor a pump at the lower end of ature, formation changes, or the like. However, it may i be desirable to restrict relative axial movement between such tubing and the casing. Accordingly, it is still are otherl object. of this invention toprovideapparatus af- ',fording a floating support for the well'tubing'as well Aas 'for the casing.

This invention possesses many other advantages and has other objects which may be made more easily` ap- Aparentfrom'a consideration of several embodiments of 'the invention. For this purpose there are shown two formsvin the' drawings accompanying and forming part Such tubing is generally supported only at its I means maintaining a suitable pressure.

cylinderexceeds a predeterminedamount.

description is not to be taken in a limiting sense, since the scopeof the invention is best defined by the appended claims.

In the accompanying drawings: v

Figure l is an axial section, largely schematic, showing one form of the invention; and

Figure 2 is a fragmentary section, showing a form of the invention. v

Referring to Figure 1, the apparatuscomprises a vertical cylinder 6 mounted on an adapter 7l havingan lexternal iiange 8 by the aid of which the cylinder Iis supported at the mouth of the well bore in any suitable mannare, as for example, by a base plate 9.

A piston structure 10 is slidable in the cylinder4 6, having a head 11 sealed in fluid tight relation with cylinder wall by an expansible seal ring 12 and a reduced skirt or extension 13, passing through a bore 14 in the upper end of the adapter 7, an expansibleseal ring 15 maintaining the skirt 13 and bore14 in iluid tight relation. The piston structure 10 and the cylinder 6 thus cooperate to form an expansible chamber 16.

The piston structure 10 has a through bore'pl7 for freely accommodating the casing C, the upper end4 portion of the bore 17 being tapered to provide a seat 18 for slips 19 which engage and support the casing C. An inflatable gasket or ring 20 is provided for sealing. be tween the piston 10 and the casing C. An important feature of this arrangement is that different sizes of casing can be readily accommodate in one apparatusby providing piston structures as 10 with suitable sized bores 17. The seal rings 12, 15 and 20 are commercially available, being made usually of artificial rubber and cooperating with the supporting member to form an annular chamber for thereception of fluid pressure to urge them to sealing condition. Thus, the iings 12 and `Ztluare in communication with the expansible chamber 16 bythe aid of ports 21 in the piston head 11, seal ring 15 communicating with the expansible chamber 16 by the aid of ports 22-a, the main port 22, to be more fully discussed hereinafter, being connected with one of the ports 22-a.

The casing string C is usually anchored at its lower end to the well formation by means of a body of cement (not shown), the upper end being so supported as to maintain the casing properly tensioned. in the present apparatus, the expansible chamber 16 is filled with a iiuid maintained under suitable pressure tourge the piston '10 upwardly, with such force as to properly tension the casing. For this purpose, a conduit 23 leads from the previously mentioned port 22 to a conventional source 'modied :of fluid pressure 24`.which may comprise a pump 'and by-pass arrangement, a'n hydraulic accumulator,g brother A branch 25 leads from Athe conduit 23 to aA point above the derrick lloor F where it is connected to a pressure gauge 26 and to a pressure tight tank 27 provided with a conventional water glass or gauge 28. Brief consideration lwill show that with a constantamount of liquid in the system, the amount of liquid in tank 2'7 Vwill be a function of the position of the piston 10 in the cyl' inder 5; as the piston goes down, the liquid level in tank 27 will rise, and vice versa. Accordingly, by observing the liquid level in the gauge glass 28,*the position of 'the vpiston 10 can be ascertained.

Appropriate shut oli valves 29 may be provided as well "-a's a drain valve 30, anda relief valve/3 1 of known type for automatically releasing fluid when the pressure in the n '.l-he tubing isti-ing?? .is .supported on the piston strucllured!).,by..t11eaid. of a cap 32l threadedly -.secured .tothe 0f.tkletlbins T. iS threaded intofthe .bOSS 33., 'extending through the chamber 35 and through'a vstuiiing b'oX` 39 011th@ cylinder headt- .In. the .farmf Eigure the tubing String T .extends through. the chamber 35, and is supported lincl ependently o f the piston lt by a threaded iiange 40 securedto va modified form of"c yl i n der head 41.. the cap 32 being @witted .I slain l. In a iioating supportfora lwel] casing, there being .a. tubings tring Within said ca singz'fa stationary member and a'relutively movable member cooperating to form Van..expansible chamber; said` casing being securedadjaentits upper Aend to said movable member; means for supplying fluid pressure tosaid chamber'to cause said movable member to at least partly support the casing; and

means for supporting said tubing string independently of said movable member. i

2. a floating support for la 4well casing,.there being a tubing string Awithin said casing: astationary member and a relatively movable member cooperating to form an enpansible chamber; said casing being. .secured 'adjacent its upper .end to .saidmovable member.; means for supplying fluid pressure to said chamber tocau'sesaid movable member to at .least partly support .the casing; and means for supporting said tubingons'aidfmo/vfable member. v

3. In a oating .support fora well casing: a vertical cylinder structure; .said casing extendingupwardly into said cylinder; apiston. slidable inO said cylinder. structure;

means on .the upper side of said piston `for ,detachably connectlngthe .upper en d Vofsaid casing with the piston; a closure for theupperend of said cylinder structure foirning a space therein above the .piston andlfreely communieating lwith said. casing; and vmeans forming a passage connected with said space. l l I i 4. In a oating support .for a wellcasing, therebeing n tubing string within said casing: a vertical cylinder .structure into which said easingl extends; a piston struc- 'ture'.slidable in said cylinder structure .adapted to engage the upper end of said casing in supporting relation; iiuid pressufre .means yforfadjustably supporting said vpiston structure; vand ineens on one of said .structures .above the upper end of the casing for supporting said tubing string.

5. In a `floating .supportfor a well casing, there being tubing stringwithin said casing: a..v.ertical cylinder v .struletureinto which Asaid casing extends; ai piston l slidable in said cylinder structureadaedmto engage the .upper end of said vcasingin supporting relation; duid-pressure means for .adjustably supporting saidv piston; andmeans on said cylindrical structure above the piston for supporting V said tubing string.

6 in n v iloating support for awell casing Atherebeing .ture flvl che? d `cas .;tendsigahpisto slidzlbley in snidcylindcr structur adapted to engage the. upper end of sajdfcasing in supporting relationguid pressure .means for. adjustably supporting said piston; and means for supporting said tubing string for movement with. said .'.sesins- I n a floatingsupportor a wellleasing,ltherelbeingo ft lvertical linder 1 Y fh structure into Al l) in said cylinder structure 'adapted to engage the upper end.. nf ...the easing. is .suppsrtins.relation .a .C .lQSilr .for

the upper end of said cylinder 4structure forming a space therein above the piston and freely communicating with said casing; means forming a passage connected with said space; and means for supplying fluid pressure to the space in said cylinder structure below the piston for operating the piston to support the casing; said tubing string eX- tending through the space above the piston; said closure including passage formingmeans cooperating with said tubing to enable a connection therewithabove said closure.

8. ln aoatingsupport for a well. ycas ing, there .being e .tilibnsstrins wthnsad' easing: @vertical Cylinder structure .into which said Acasing extends.; .a .pistonslidable in said cylinder .structure adapted to engage the upper end of they casing in 'supporting' relationga closure for the upper endofsaidcylinder structure forming a space therein above the piston and freely communicating with said casing; means forming a passage connected with said space; means for supplying iluid pressure to -[the spacein said cylinder.structure below the piston for operating the piston'tosuppo'rtthe casing; said tubing string extending through the spaceabove thepistoi and means whereby'jsaidclosureis'a'dapted to support said tubing and provides aport communicating therewtih. 9. In aiifoating support for a well casing, there being a tubing string within"said casing: a've'rtieal cylinder structure into .whichhsaid'casing extends; apiston slidable lin said cylinder'structurel-adapted to engage the upper end of the'ca'sing in'supp'ortingrelation; a`closure for the upper end 4of .said cylinder structure formingv a space therein above the piston and freely communicating with said casing; means forming a passage connected withsaid space; means for supplyingfiiiiidpressure tothe space in cylinder s-t'ructure'fbelow the piston lfor operatingthe piston tosupport the casing; and means on said piston for supportingsaid tubing string; said tubing stringfhaving an extension passingr upwardly through the space above the pist-onV and'slidably through an opening i'nsaid closure.

l0. In a support vfor a well ycasing Ihaving a tubing string therein; acylinder lstructure adapted tfo receive the casing and thel tubing string; a piston structure slidable vin said cylinder structure; rnean'sfor'suspendin'g 4the'cas- Iing from said piston vstructure; fluid Ypressure means for adjustabiy supporting said piston Vstructure while the latter supports said cas ing=;.and means on 'onegofsaid structures vfor supporting "said tubing string.

ll. In ao'ating supportfor afwell casing: a vertical cylinder structure; a piston structure slidable therein having a head engaging the` cylinder walland a tubular skirtfextending downwardly through. the bottom cylinder head; said piston structure having a throughbore for slidably accommodating the'ca'sing the upper vendportion of said 'borenbeing 'e larged and tapered to l'prcn/id'e'fan slip seat accessible th ough the uppe'rlend fof said cylinder' structureandQslip'son *aiy at forengag'ing th'e'ca'sing isupporglrlao. 1 2. 'In a Supportfor oil well casing: a stationary member; a relativelymovable'fmembe'means for securing said casing for supportl by said movable 'member whereby upward movement of saidniember tensions said casing; meansvfor supporting said movablel memberin vadjusted vertical relation onine Stationary member to varyfthe tensionof saidjcasing; adfeans res in the casinguin 'eicessofa vpredetermined tension and connected with said stationary member at. a Ypoint below the lowermostpos'ition attained by said .movable vmember for controlling the movement o'fl'said movable member from all`vertically ..adjusted positions of said movable ymember in faccordance vyvitlrthetension in saidl casing. 'l 1 3. lIn a .support 'fon a well" easing;l af stationary'member; fa movablefmember operatively" a'ssoeiate'd with said statiouarymember; means forLsuspending said casing from said movable member so that the load on the casing is continuously applied to said movable member; means for supporting said movable member in adjusted relation on said stationary member to vary the load on said casing; and means operatively connected with said stationary member at a point below the lowermost position attained by said movable member operable responsive to a load 0n said casing in excess `of a predetermined load for relieving the excess load and controlling the movement of said movable member from al1 positions in which the movable member is supported by said supporting means.

References Cited in the file of this patent UNITED STATES PATENTS Chase May 15, 1928 Gattrell Apr. 12, 1932 List May 16, 1933 Knowlton et al. June 13, 1933 Howard et a1. Dec. 11, 1934 Wineman Oct. 14, 1941 

